High temperature molten salt thermal electrochemical cells are widely used as power sources for projectiles, rockets, bombs, mines, missiles, decoys, jammers and torpedoes. They are also used as fuses. Thermal electrochemical cells are reserve-type cells that can be activated by heating with a pyrotechnic heat source such as zirconium and barium chromate powders or mixtures of iron powder and potassium perchlorate. Early thermal batteries employed magnesium or calcium as the anode, an eutectic mixture of lithium chloride and potassium chloride as the electrolyte and cathodes of metal oxides such as copper oxide (CuO), iron oxide (Fe.sub.2 O.sub.3), vanadium oxide (V.sub.2 O.sub.5), tungsten oxide (WO.sub.3) and metal chromates such as calcium chromate and potassium chromate. More recent thermal electrochemical cells use alloys of lithium such as lithium-aluminum, lithium-boron and lithium-silicon as anodes, an eutectic mixture of lithium chloride and potassium chloride as the electrolyte and iron disulfide as the cathode material. The use of lithium alloys as anodes instead of calcium and magnesium has resulted in higher energy densities. Further, the lithium alloy/iron disulfide thermal electrochemical cell has demonstrated improved performance over the older magnesium or calcium thermal electrochemical cells. The lithium-alloy/iron disulfide electrochemical cell is now widely used for various military applications as mentioned above and has an open circuit voltage of about 1.7 volts.
It would still be more desirable, however, for the thermal electrochemical cell to have an even higher open circuit voltage, a greater energy density, and to exhibit flat discharge plateaus under load at voltages consistently above 2.0 volts.